Reinforcing structure of UHPC-NC interface in steel-concrete composite beam
By using steel components to fix the connection at the UHPC-NC interface of the steel-concrete composite beam, the problem of easy cracking of the interface is solved, and the bonding strength and construction convenience are improved.
Patent Information
- Application Number
- CN202421616517.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-07-10
AI Technical Summary
In steel-concrete composite beams, the UHPC-NC interface is prone to cracking, affecting the durability and bearing capacity of the bridge. The existing interface processing methods have problems such as large workload, difficulty in ensuring interface strength and difficulty in construction.
Steel components are used instead of conventional stud shear parts, and the UHPC and NC bridge panels are fixedly connected near the UHPC-NC interface to ensure the bonding performance of the interface.
The bonding strength of the UHPC-NC interface is improved, and the interface is avoided cracking before the UHPC bridge deck is simplified, and the construction process is not increased without increasing the interface reinforcement rate.
Smart Images
Figure CN222935826U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the technical field of bridges, and specifically relates to an enhanced structure for the UHPC-NC interface in a steel-concrete composite beam. Background Art
[0002] Compared with reinforced concrete beam structures, steel-concrete composite beam bridges have the advantages of light self-weight, small cross-sectional dimensions, and good ductility of the beam; compared with steel beams, they can reduce the steel consumption, increase the stiffness, and enhance the structural stability and integrity, and have been widely used in bridge structures. For continuous composite beam bridges, in the negative moment area near the middle support, since the upper concrete bridge deck is in tension and the lower steel beam is in compression, and normal concrete (NC) has poor tensile performance, the concrete bridge deck is prone to cracking, which affects the durability and bearing capacity of the bridge. Ultra-high performance concrete (UHPC), also known as reactive powder concrete, has ultra-high mechanical properties (compressive and tensile properties) and ultra-high durability. Applying UHPC to the negative moment area of a continuous composite beam bridge can effectively limit the development of cracks in the bridge deck, thereby improving the strength and durability of the composite bridge structure. Considering economy, only UHPC is used to replace the NC bridge deck in the negative moment area, so there will be a UHPC-NC interface where UHPC and NC bridge decks intersect; the interface is a weak link and is prone to cracking prior to the UHPC bridge deck under the action of loads, thus losing the function of UHPC to limit the development of cracks in the bridge deck.
[0003] In order to increase the bonding strength of the interface, the current conventional interface treatment methods include roughening, grooving, and densifying reinforcement, etc. The disadvantages of these methods are mainly as follows:
[0004] 1. Large workload: Roughening and grooving require workers to use mechanical equipment for construction, often consuming a large amount of manpower and material resources.
[0005] 2. Difficulty in ensuring interface strength: Separate treatment methods are difficult to ensure the bonding strength of the interface, and often multiple treatment methods are required to ensure the bonding of the interface.
[0006] 3. Difficult construction: Densifying reinforcement increases the reinforcement ratio at the interface. Although it can increase the interface strength, it makes it difficult to vibrate the concrete densely at this place, increasing the construction difficulty to a certain extent.
[0007] Therefore, there is an urgent need for a new enhanced structure for the UHPC-NC interface to solve the above technical problems Utility Model Content
[0008] The objective of the embodiments of this application is to provide a reinforcement structure for the UHPC-NC interface in a steel-concrete composite beam. Near the UHPC-NC interface of a composite beam bridge, steel components are used to replace conventional stud shear connectors, thereby ensuring the bonding performance of the UHPC-NC interface and preventing the interface from cracking prior to the UHPC bridge deck. At the same time, the construction difficulty is not increased, and thus at least one technical problem involved in the background art can be solved.
[0009] To solve the above technical problems, the present application provides the following technical solutions:
[0010] The embodiments of the present application provide a reinforcement structure for the UHPC-NC interface in a steel-concrete composite beam, including a steel beam, a UHPC bridge deck, an NC bridge deck, and steel components. The UHPC bridge deck and the NC bridge deck are spliced horizontally and arranged on the steel beam. The steel components are fixedly arranged on the steel beam, and the steel components span across the joint between the UHPC bridge deck and the NC bridge deck and fixedly connect the UHPC bridge deck and the NC bridge deck.
[0011] Optionally, it further includes studs with one end fixedly arranged on the steel beam, and the other end of the studs is embedded and fixed in the UHPC bridge deck or the NC bridge deck.
[0012] Optionally, the steel components are strip-shaped and arranged along the length direction of the steel beam.
[0013] Optionally, at least two steel components are arranged along the width direction of the steel beam.
[0014] Optionally, the steel components are arranged in parallel at intervals.
[0015] Optionally, at least two rows of studs are arranged along the width direction of the steel beam, and the number of rows of studs is equal to the number of steel components.
[0016] Optionally, the height of the steel components is half of the thickness of the UHPC bridge deck and the NC bridge deck.
[0017] Optionally, the steel components are provided with through reserved holes, and part of the steel bars inside the UHPC bridge deck or the NC bridge deck pass through the reserved holes.
[0018] Optionally, the diameter of the reserved holes is 1-2 mm larger than the diameter of the steel bars.
[0019] Optionally, the steel components are symmetrically arranged with respect to the joint, and both ends of the steel components extend 2-3 meters in the direction away from the joint.
[0020] The beneficial effects of the embodiments of the present application are as follows:
[0021] 1. Convenient construction: Steel members are used to replace the stud connectors at the interface, which can make up for the discontinuity of steel fibers at the interface without increasing the interface reinforcement ratio, and avoid the situation that it is difficult to vibrate the deck concrete due to too high steel bar reinforcement ratio.
[0022] 2. Positioning template: The steel members are in a perforated form, and the hole diameter is slightly larger than the size of the deck steel bars, so that the deck steel bars can pass through them and serve as a template for positioning the deck steel bars.
[0023] 3. Strengthen the UHPC-NC interface: Compared with the existing UHPC-NC interface, due to the discontinuity of the steel fibers in the UHPC at the interface, the crack resistance strength will be weakened, and the UHPC-NC interface becomes a weak link of the deck. In this application, continuous steel members are used to make the interface have a continuous steel bar ratio, make up for the discontinuity of the steel fibers, and enhance the bonding strength of the UHPC-NC. Description of the drawings
[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where:
[0025] Figure 1 is a schematic diagram of the steel section of the UHPC-NC enhanced interface provided by the embodiment of the present application;
[0026] Figure 2 is provided by the embodiment of the present application Figure 2 is an elevation view of the stud not shown;
[0027] Figure 3 is provided by the embodiment of the present application Figure 2 is a side view;
[0028] Figure 4 is a schematic diagram of the reinforcement layout of the deck of the UHPC-NC enhanced interface structure provided by the embodiment of the present application;
[0029] Figure 5 is an overall schematic diagram of the UHPC-NC enhanced interface provided by the embodiment of the present application.
[0030] In the figure, 1. NC deck; 2. UHPC deck; 3. Steel beam; 4. Perforated steel section; 5. Stud; 6. Reserved hole; 7. Deck steel bar. Detailed implementation manners
[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
[0032] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order different from those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same category, and the number of objects is not limited. For example, the first object can be one or multiple. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means an "or" relationship between the associated objects before and after.
[0033] Please refer to Figures 1-5 As shown, Embodiment 1 of the present application provides a reinforcement structure for the UHPC-NC interface in a steel-concrete composite beam, including an NC deck slab 1, a UHPC deck slab 2, a steel beam 3, and a steel member 4. The NC deck slab 1 and the UHPC deck slab 2 are spliced horizontally and arranged on the steel beam 3. The steel member 4 is fixedly arranged on the steel beam 3, and the steel member 4 straddles the joint of the NC deck slab 1 and the UHPC deck slab 2 and fixedly connects the NC deck slab 1 and the UHPC deck slab 2.
[0034] The steel member 4 is strip-shaped and arranged along the length direction of the steel beam 3.
[0035] In some embodiments, at least two steel members 4 are arranged along the width direction of the steel beam 3, and the steel members 4 are arranged in parallel at intervals.
[0036] The height of the steel member 4 is half of the thickness of the NC deck slab 1 and the UHPC deck slab 2. In this way, sufficient structural strength can be ensured at the joint of the NC deck slab 1 and the UHPC deck slab 2 and the steel member 4.
[0037] The steel member 4 is provided with a through reserved hole 6, and part of the steel bars 7 inside the UHPC deck slab 2 or the NC deck slab 1 pass through the reserved hole 6.
[0038] The diameter of the reserved hole 6 is 1-2 mm larger than the diameter of the steel bar 7. In this way, when pouring the bridge deck, the steel bar 7 inside it can use the reserved hole 6 as a positioning hole and pass through the reserved hole 6. After the bridge deck is formed, since the steel bar 7 of the bridge deck passes through the steel member 4, the connection between the steel member 4 and the bridge deck is more firm.
[0039] Furthermore, the steel members 4 are symmetrically arranged with respect to the joint, and both ends of the steel members 4 extend 2-3 meters in the direction away from the joint, with a total length of 4-6 meters. The steel members 4 are uninterrupted and transition from the UHPC bridge deck 2 to the NC bridge deck 1 through the UHPC-NC interface, so that there is a continuous steel ratio at the interface, making up for the discontinuity of the steel fibers and enhancing the bonding strength of UHPC-NC.
[0040] In Embodiment 1, both the steel beam 3 and the steel member 4 are in the shape of "I".
[0041] In some embodiments, the strengthening structure provided by the present application further includes a stud 5 with one end fixedly arranged on the steel beam 3, and the other end of the stud 5 is embedded and fixed in the UHPC bridge deck 2 or the NC bridge deck 1.
[0042] There are at least two rows of the studs 5 arranged along the width direction of the steel beam 3, and the number of rows of the studs 5 is equal to the number of the steel members 4.
[0043] It should be noted that the thickness of the steel member 4 is determined according to the size of the stud 5, so that the area of the steel member 4 is consistent with the area of the stud 5, ensuring that the steel ratio is not increased at the interface and facilitating the pouring of concrete.
[0044] The construction process of the strengthening structure of the UHPC-NC interface in the steel-concrete composite beam provided by the present application is as follows:
[0045] Step 1: Prefabricate the steel beam 3, and weld continuous steel members 4 with reserved holes 6 near the UHPC-NC interface, and weld studs 5 as connectors in other areas, as Figure 1 shown;
[0046] Step 2: Erect the steel beam 3 on site, set up the formwork for pouring the bridge deck, and arrange the steel bars 7 of the bridge deck with the reserved holes 6 of the steel members 4 as the formwork, as Figure 4 shown;
[0047] Step 3: Pour the NC bridge deck 1 and the UHPC bridge deck 2, and wait until the concrete is formed as Figure 5 shown; The NC bridge deck 1 and the UHPC bridge deck 2 are connected to the steel beam 3 through continuous steel members 4 or studs 5.
[0048] The beneficial effects of the embodiments of the present application are as follows:
[0049] 1. Convenient construction: By using steel members to replace the stud connectors at the interface, the disadvantage of discontinuous steel fibers at the interface can be compensated without increasing the interface reinforcement ratio, avoiding the situation where it is difficult to vibrate the deck concrete due to too high a steel bar reinforcement ratio.
[0050] 2. Positioning template: The steel members are in a perforated form, and the hole diameter is slightly larger than the size of the deck steel bars, enabling the deck steel bars to pass through them and serving as a template for positioning the deck steel bars.
[0051] 3. Strengthening the UHPC-NC interface: Compared with the existing UHPC-NC interface, where the anti-cracking strength is weakened due to the discontinuous steel fibers in the UHPC at the interface and the UHPC-NC interface becomes a weak link in the deck, the present application uses continuous steel members, resulting in a continuous steel reinforcement ratio at the interface, compensating for the discontinuity of the steel fibers and enhancing the bonding strength of the UHPC-NC.
[0052] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.
Claims
1. A reinforcement structure of UHPC-NC interface in a steel-concrete composite beam, characterized in that: It includes a steel beam, a UHPC bridge deck, a NC bridge deck and a steel member. The UHPC bridge deck and the NC bridge deck are spliced in the horizontal direction and arranged on the steel beam. The steel member is fixed on the steel beam, and the steel member spans the joint between the UHPC bridge deck and the NC bridge deck and fixedly connects the UHPC bridge deck and the NC bridge deck.
2. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 1, characterized in that: It also includes a bolt with one end fixed on the steel beam, and the other end of the bolt is embedded and fixed in the UHPC bridge deck or the NC bridge deck.
3. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 2, characterized in that: The steel component is in the shape of an elongated strip and is arranged along the length direction of the steel beam.
4. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 3, characterized in that: At least two steel members are arranged along the width direction of the steel beam.
5. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 4, characterized in that: The steel components are arranged in parallel and at intervals.
6. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 4, characterized in that: At least two rows of the studs are arranged along the width direction of the steel beam, and the number of rows of the studs is equal to the number of the steel components.
7. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 1, characterized in that: The height of the steel member is half the thickness of the UHPC bridge deck and the NC bridge deck.
8. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 1, characterized in that: The steel member is provided with a through reserved hole, and part of the steel bars inside the UHPC bridge deck or the NC bridge deck are arranged through the reserved hole.
9. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 8, characterized in that: The diameter of the reserved hole is 1-2 mm larger than the diameter of the steel bar.
10. The reinforcement structure of the UHPC-NC interface in the steel-concrete composite beam according to claim 1, characterized in that: The steel components are symmetrically arranged about the joint, and both ends of the steel components extend 2-3 meters away from the joint respectively.